Composite structures, heater apparatus, fast light-off exhaust aftertreatment systems, and methods of manufacturing and using same

Abstract

A composite structure, exhaust aftertreatment system, and method of manufacture. The composite structure includes a body that includes an array of intersecting walls that form a plurality of channels extending in an axial direction through the body such that adjacent channels are located on opposite sides of each wall. A composite material of the body includes a first phase of a porous glass or ceramic containing material. The first phase includes an internal interconnected porosity. A second phase of an electrically conductive material is included that is a continuous, three-dimensional, interconnected, electrically conductive phase at least partially filling the internal interconnected porosity of the first phase, which creates an electrical path through at least some of the walls in a lateral direction perpendicular to the axial direction between the opposite sides of the walls.

What is claimed is: 
     
       1. A composite structure, comprising:
 a body comprising an array of intersecting walls that form a plurality of channels extending in an axial direction through the body such that adjacent channels are located on opposite sides of each wall, wherein each wall has a wall thickness that is defined between the opposite sides of that wall, and the wall thicknesses of a plurality of the walls extend in a lateral direction that is perpendicular with respect to the axial direction, wherein a composite material of the body comprises:
 a first phase comprising a monolith honeycomb body of a porous glass or ceramic containing material, wherein the first phase comprises an internal interconnected porosity; and 
 a second phase of an electrically conductive material, wherein the second phase is a continuous, three-dimensional, interconnected, electrically conductive phase at least partially filling the internal interconnected porosity of the first phase to create a continuous electrical path that extends in the lateral direction across the body by extending in the lateral direction through the wall thicknesses of the walls in the plurality of walls in a lateral direction perpendicular to the axial direction between the opposite sides of the walls. 
 
 
     
     
       2. The composite structure of  claim 1 , wherein the electrically conductive material comprises a sintered metal phase. 
     
     
       3. The composite structure of  claim 1 , wherein the second phase creates an electrical connection across the body between opposite sides of the body in the lateral direction perpendicular to the axial direction of the body. 
     
     
       4. The composite structure of  claim 3 , wherein the second phase also creates an electrical connection between opposing axial faces of the body. 
     
     
       5. The composite structure of  claim 1 , wherein the second phase is also formed at least partially along exterior surfaces of the walls. 
     
     
       6. The composite structure of  claim 1 , wherein the second phase comprises greater than or equal to 10% of a solid volume of the composite structure. 
     
     
       7. The composite structure of  claim 1 , wherein the first phase constitutes from 25% to 90% of a solid volume of the composite structure, and the second phase constitutes from 10% to 75% of the solid volume of the composite structure. 
     
     
       8. The composite structure of  claim 1 , wherein the electrically conductive material of the second phase is an electrically conductive metal. 
     
     
       9. The composite structure of  claim 1 , wherein the electrically conductive metal comprises an Fe-containing alloy an Fe-, Cr-, and Al-containing alloy, or a nickel-chromium containing alloy. 
     
     
       10. The composite structure of  claim 1 , wherein the second phase incompletely fills the internal, interconnected porosity of the first phase and leaves residual open porosity in the walls. 
     
     
       11. The composite structure of  claim 1 , wherein a catalyst material is disposed on the walls, in an open porosity of the walls, or both. 
     
     
       12. The composite structure of  claim 1 , wherein the porous glass or ceramic-containing material comprises cordierite, aluminum titanate, alumina, silicon carbide, silicon nitride, mullite, sappherine, spinel, calcium aluminate, zirconium phosphate, β-spodumene, β-eucryptite(LiAlSiO 4 ), a cordierite-glass ceramic, fused silica, doped fused silica, or combinations thereof. 
     
     
       13. The composite structure of  claim 1 , wherein the composite material comprises an electrical conductivity of between 15 S/cm and 300 S/cm. 
     
     
       14. The composite structure of  claim 1 , wherein the electrically conductive material of the second phase has an electrical resistivity of less than 1.2×10 −6  Ohm-m. 
     
     
       15. The composite structure of  claim 1 , wherein the second phase is present in the internal, interconnected porosity at a loading level of at least 200 g/L with respect to a representative volume of the composite structure, wherein the representative volume is determined as a closed frontal area of the first phase, inclusive of the internal interconnected porosity, multiplied by an axial length of the first phase. 
     
     
       16. The composite structure of  claim 15 , wherein the loading level is at least 1,200 g/L of the representative volume of the composite structure. 
     
     
       17. The composite structure of  claim 15 , wherein the loading level is at least 150 cm 3 /L of the representative volume of the composite structure. 
     
     
       18. The composite structure of  claim 1 , comprising cutout portions that create a serpentine pattern for the array of walls by separating portions of the walls from each other. 
     
     
       19. The composite structure of  claim 18 , wherein the electrical conductivity is from 1,000 S/cm to 2,500 S/cm. 
     
     
       20. The composite structure of  claim 1 , wherein the internal, interconnected porosity of the first phase, absent the second phase, comprises:
 an average bulk porosity of the internal, interconnected porosity from 40% to 80%; and 
 a median pore size from 5 μm to 40 μm. 
 
     
     
       21. An exhaust aftertreatment system comprising a heater assembly comprising the composite structure of  claim 1  arranged as a resistive heater element, and an exhaust aftertreatment component positioned adjacent to the heater assembly. 
     
     
       22. The exhaust aftertreatment system of  claim 21 , wherein the exhaust aftertreatment component is a catalyzed substrate or a particulate filter. 
     
     
       23. A composite structure, comprising:
 a honeycomb body of intersecting walls forming a plurality of channels, wherein a composite material of the body comprises: 
 a first phase of a porous glass or ceramic containing material, wherein the first phase comprises an internal interconnected porosity having a porosity of 40% to 80% and a median pore size from 5 μm to 40 μm; and 
 a second phase of an electrically conductive material, wherein the second phase is present in the internal, interconnected porosity at a loading level of at least 25 cm 3 /L with respect to a representative volume of the composite structure, wherein the representative volume is determined as a closed frontal area of the first phase, inclusive of the internal interconnected porosity, multiplied by an axial length of the first phase; 
 wherein the first phase constitutes from 25% to 90% of a solid volume of the composite structure, and the second phase constitutes from 10% to 75% of the solid volume of the composite structure. 
 
     
     
       24. A composite structure comprising:
 a body comprising an array of intersecting walls that form a plurality of channels extending in an axial direction through the body such that adjacent channels are located on opposite sides of each wall, wherein a composite material of the body comprises:
 a first phase of a porous glass or ceramic containing material, wherein the first phase comprises an internal interconnected porosity; and 
 a second phase of an electrically conductive material, wherein the second phase is a continuous, three-dimensional, interconnected, electrically conductive phase at least partially filling the internal interconnected porosity of the first phase to create an electrical path through at least some of the walls in a lateral direction perpendicular to the axial direction between the opposite sides of the walls, 
 
 wherein the second phase comprises greater than or equal to 10% of a solid volume of the composite structure. 
 
     
     
       25. A composite structure comprising:
 a body comprising an array of intersecting walls that form a plurality of channels extending in an axial direction through the body such that adjacent channels are located on opposite sides of each wall, wherein a composite material of the body comprises:
 a first phase of a porous glass or ceramic containing material, wherein the first phase comprises an internal interconnected porosity; and 
 a second phase of an electrically conductive material, wherein the second phase is a continuous, three-dimensional, interconnected, electrically conductive phase at least partially filling the internal interconnected porosity of the first phase to create an electrical path through at least some of the walls in a lateral direction perpendicular to the axial direction between the opposite sides of the walls, and 
 
 cutout portions that create a serpentine pattern for the array of walls by separating portions of the walls from each other.